Spindle Bearings in an old South Bend Lathe

Spindle Bearings in an old South Bend Lathe

Post by Bruce Mille » Thu, 06 Jan 2000 04:00:00



I have an old South Bend lathe with plain spindle bearings. The bearings
seem to be loose. I know that this type of plain bearing can be shimmed,
but how much wear can be taken up with this method?

I chucked a 2" piece of C1018 in the lathe. Then I put a dial indicator
on the side of the 2" steel bar in the chuck and zeroed the indicator.
Then I pushed the bar away from me as hard as I could. The indicator
measured .007 of movement. The same thing happens when I pull the steel
bar toward me. When I let go of the bar the indicator does not return
exactly to zero, I sits between 0 to .002 in the same direction as I
applied the force.

I did pull up and press down on the bar too, but I didn't move the
indicator to measure the play. When pulling up or pressing down on the
bar, the rear spindle bearing makes a clunking noise.

I guess this explains the chatter.

I have not taken  the spindle bearings caps off yet, I am chicken I
guess.

My lathe seems to be a steel spindle running in a cast iron headstock
with shims. What is the correct procedure for shimming the spindle
bearings?

By the way, this is an old single tumbler 14.5" plain bearing lathe made
in 1942.

Thanks,
BAMiller

 
 
 

Spindle Bearings in an old South Bend Lathe

Post by Erich Coine » Sat, 08 Jan 2000 04:00:00


Quote:

> My lathe seems to be a steel spindle running in a cast iron headstock
> with shims. What is the correct procedure for shimming the spindle
> bearings?

> By the way, this is an old single tumbler 14.5" plain bearing lathe made
> in 1942.

> Thanks,
> BAMiller

There is a shim between the main casting and the bearing cap. It is
actually a whole stack of thin shims laminated together.
Remove the cap and then peel one layer of the shim stack off and
reinstall.  I think each shim is 0.002 inches thick. Take an equal
number of shims leaves from each side of the cap.
Thats it.
Erich

 
 
 

Spindle Bearings in an old South Bend Lathe

Post by Richard C. Penne » Sat, 08 Jan 2000 04:00:00


Hi,

  Lindsay has a book "How to run a lathe" 1942 by South Bend cheap.
www.lindsaybks.com    The fellow responding is correct about the shims.
There was an article recently, maybe some kind soul can put their hands
on it for you..
toff

Quote:


> > My lathe seems to be a steel spindle running in a cast iron headstock
> > with shims. What is the correct procedure for shimming the spindle
> > bearings?

> > By the way, this is an old single tumbler 14.5" plain bearing lathe made
> > in 1942.

> > Thanks,
> > BAMiller

> There is a shim between the main casting and the bearing cap. It is
> actually a whole stack of thin shims laminated together.
> Remove the cap and then peel one layer of the shim stack off and
> reinstall.  I think each shim is 0.002 inches thick. Take an equal
> number of shims leaves from each side of the cap.
> Thats it.
> Erich

 
 
 

Spindle Bearings in an old South Bend Lathe

Post by Marshall Pharoa » Sun, 09 Jan 2000 04:00:00


There is a procedure to follow for the box bearings (bronze).  Make sure you don't have one of these before you start ripping it
apart.  What size is your lathe?  You can find out what the bearings are at www.southbendlathecorp.com if you get the serial number
of the bed.  This allows you to look up the specs for some of the lathes.  The shims will help for sure with vertical movment, but
may not allow all of the horizontal movement to be removed.
Quote:

> I have an old South Bend lathe with plain spindle bearings. The bearings
> seem to be loose. I know that this type of plain bearing can be shimmed,
> but how much wear can be taken up with this method?

> I chucked a 2" piece of C1018 in the lathe. Then I put a dial indicator
> on the side of the 2" steel bar in the chuck and zeroed the indicator.
> Then I pushed the bar away from me as hard as I could. The indicator
> measured .007 of movement. The same thing happens when I pull the steel
> bar toward me. When I let go of the bar the indicator does not return
> exactly to zero, I sits between 0 to .002 in the same direction as I
> applied the force.

> I did pull up and press down on the bar too, but I didn't move the
> indicator to measure the play. When pulling up or pressing down on the
> bar, the rear spindle bearing makes a clunking noise.

> I guess this explains the chatter.

> I have not taken  the spindle bearings caps off yet, I am chicken I
> guess.

> My lathe seems to be a steel spindle running in a cast iron headstock
> with shims. What is the correct procedure for shimming the spindle
> bearings?

> By the way, this is an old single tumbler 14.5" plain bearing lathe made
> in 1942.

> Thanks,
> BAMiller

 
 
 

Spindle Bearings in an old South Bend Lathe

Post by mulli.. » Sun, 09 Jan 2000 04:00:00




Quote:
> Then I pushed the bar away from me as hard as I could. The indicator
> measured .007 of movement. The same thing happens when I pull the
> steel bar toward me.

Which implies to me that you have four*** thousanths of clearance in
the bearings, which is a lot.

First you have to re-do the measurement, because you have done it
a bit incorrectly.  Not a lot wrong, but it is important to do this
right as it can save you a lot of time later on.

Remove the CRS you have in the chuck.  Remove the chuck from the
spindle.  Remove any backplates or whatnot from the spindle nose as
well, so you are looking right at the the threaded portion of the
spindle as it emerges from the headstock.  Now put your indicator
directly on the unthreaded part of the spindle (the register diameter)
as it emerges from the headstock, as close to the headstock casting
as possible consistent with getting the indicator to function properly.

Have the indicator mounted so it measures the up/down play on the
spindle.  Now push down on on a s***of rod, or a broomstick, or
whatever, that is in the spindle hole of the machine, and while
doing so, zero out the indicator.  Now push up on the stick and
note the reading on the dial.  This is the TIR that will have
to be removed by subtracting shims from under the cap.

The readings you took on the stock in the chuck are overestimating
the clearance, I think.

If this machine is like most SB lathes I know (with the exception of
the 9" ones) then there will be bolts that hold the bearing caps
down, and then there will be two pipe plugs between them on top of
the cap.  If this is the case, DO NOT attempt to remove the bearing
caps before doing this first:  remove the pipe plugs and under them
you will see screws (either slotted or allen head) which must be
removed first.

These screws pull up on an expander wedge that is locked into the
bearing shell inside the cap.  Attempting to remove the cap (by force)
without removing those screws will destroy the bearing pretty well.

Once the cap is off, look for the shims that have been mentioned.
There is a shim pack with two thou shims all soldered together which
will total something like 20 thou in a new machine, and then a single
one thou shim that you can add or suptract to get the clearance just
right.  Try to keep the front and rear shims the same thickness in
each of the headstock bearings.  You should adjust both bearings in
this fashion, of course.

If the spindle clunks then things got pretty worn, and I hope you
have the shims to tighten it up.  Why did it get so worn, was this
machine abused/neglected?  Was it run without oil?  There should be
two large oil cups and they should be full of oil when it is running.
There must be a wick under each bearing to supply oil to them, and
if they are missing or damaged then the machine will wear rapidly,
even if you snug it up again.  Best is when the oil does drip a bit
from the bottom of the spindle nose during operation, as then you
*know* the bearing is getting oil.

Good luck, please report back and let us know what you discover
upon further inspection.

Jim

Sent via Deja.com http://www.FoundCollection.com/
Before you buy.

 
 
 

Spindle Bearings in an old South Bend Lathe

Post by Phil Juve » Sun, 09 Jan 2000 04:00:00


I have a plain bearing 1941 SB 9" Mdl B. When I checked my spindle I took
the chuck off and used a brass rod inserted in the spindle bore. I believe
this is how SB recommends it be done. Mine was about .003 at worst. SB
recommends it be between .001 and .002. I took the bearing cap nearest to
the chuck off and removed the shim. I got some steel shim stock that was
.001 thinner, traced the shape of the old shim, and put it back in. That
was all there was to it. Some of the old SB lathes had a peel off shim. It
was a shim made up of laminated .001 shim stock. You just peeled off one
.001 layer at  a time.

PJ

Quote:

> I have an old South Bend lathe with plain spindle bearings. The bearings
> seem to be loose. I know that this type of plain bearing can be shimmed,
> but how much wear can be taken up with this method?

> I chucked a 2" piece of C1018 in the lathe. Then I put a dial indicator
> on the side of the 2" steel bar in the chuck and zeroed the indicator.
> Then I pushed the bar away from me as hard as I could. The indicator
> measured .007 of movement. The same thing happens when I pull the steel
> bar toward me. When I let go of the bar the indicator does not return
> exactly to zero, I sits between 0 to .002 in the same direction as I
> applied the force.

> BAMiller

 
 
 

Spindle Bearings in an old South Bend Lathe

Post by Robert Bisset » Sun, 09 Jan 2000 04:00:00


Quote:


> > My lathe seems to be a steel spindle running in a cast iron headstock
> > with shims. What is the correct procedure for shimming the spindle
> > bearings?

> > By the way, this is an old single tumbler 14.5" plain bearing lathe made
> > in 1942.

> > Thanks,
> > BAMiller

> There is a shim between the main casting and the bearing cap. It is
> actually a whole stack of thin shims laminated together.
> Remove the cap and then peel one layer of the shim stack off and
> reinstall.  I think each shim is 0.002 inches thick. Take an equal
> number of shims leaves from each side of the cap.
> Thats it.
> Erich

---

 Here is a quote from the South Bend Maintenance and Parts List dated 6-1-65.
   Got this from a local machinery dealer when I was looking for parts for
   my 1944 10" SB. Remove the chuck or face place and use a bar that will fit
   the spindle hole

 " Checking the Headstock

   With the indicator set on the spindle as near to the shoulder as possible,
   force spindle down and then exert about a 75 lb.lift. If the reading
   indicates a movement of over .001" the bearing cap at the front end will
   have to be removed and a .0015" lamination peeled off the laminated  shim
   on one side. If necessary repeat on the other side.

     If the reading indicates a movement of less than .0007", a .0015"
   lamination will have to be added to the existing shims.

   Follow same procedure for test at small bearing end. "

    I double-checked the numbers above .

Bob
---